// CodeMirror, copyright (c) by Marijn Haverbeke and others
// Distributed under an MIT license: http://codemirror.net/LICENSE
/**
 * @modifier NHN Ent. FE Development Lab <dl_javascript@nhnent.com>
 */
import CodeMirror from 'codemirror';

/*eslint-disable */
var listRE = /^(\s*)(>[> ]*|[*+-] \[[x ]\]\s|[*+-]\s|(\d+)([.)]))(\s*)/,
    emptyListRE = /^(\s*)(>[> ]*|[*+-] \[[x ]\]|[*+-]|(\d+)[.)])(\s*)$/,
    unorderedListRE = /[*+-]\s/;

CodeMirror.commands.indentOrderedList = function (cm) {
    if (cm.getOption("disableInput")) return CodeMirror.Pass;
    var ranges = cm.listSelections();
    for (var i = 0; i < ranges.length; i++) {
        var pos = ranges[i].head;
        var line = cm.getLine(pos.line);
        var cursorBeforeTextInline = line.substr(0, pos.ch);

        if (listRE.test(cursorBeforeTextInline) || cm.somethingSelected()) {
            cm.indentSelection("add");
        } else {
            cm.execCommand("insertSoftTab");
        }
    }
    cm.execCommand('fixOrderedListNumber');
};

CodeMirror.commands.newlineAndIndentContinueMarkdownList = function(cm) {
  if (cm.getOption("disableInput")) return CodeMirror.Pass;
  var ranges = cm.listSelections(), replacements = [];
  for (var i = 0; i < ranges.length; i++) {
    var pos = ranges[i].head;
    var eolState = cm.getStateAfter(pos.line);
    var inList = eolState.list !== false;
    var inQuote = eolState.quote !== 0;

    var line = cm.getLine(pos.line), match = listRE.exec(line);
    var cursorBeforeBullet = /^\s*$/.test(line.slice(0, pos.ch));
    if (!ranges[i].empty() || (!inList && !inQuote) || !match || cursorBeforeBullet) {
      cm.execCommand("newlineAndIndent");
      return;
    }
    if (emptyListRE.test(line)) {
      if (!/>\s*$/.test(line)) cm.replaceRange("", {
        line: pos.line, ch: 0
      }, {
        line: pos.line, ch: pos.ch + 1
      });
      replacements[i] = "\n";
    } else {
      var indent = match[1], after = match[5];
      var numbered = !(unorderedListRE.test(match[2]) || match[2].indexOf(">") >= 0);
      var bullet = numbered ? (parseInt(match[3], 10) + 1) + match[4] : match[2].replace("x", " ");
      replacements[i] = "\n" + indent + bullet + after;

      if (numbered) incrementRemainingMarkdownListNumbers(cm, pos);
    }
  }

  cm.replaceSelections(replacements);
};

// Auto-updating Markdown list numbers when a new item is added to the
// middle of a list
function incrementRemainingMarkdownListNumbers(cm, pos) {
  var startLine = pos.line, lookAhead = 0, skipCount = 0;
  var startItem = listRE.exec(cm.getLine(startLine)), startIndent = startItem[1];

  do {
    lookAhead += 1;
    var nextLineNumber = startLine + lookAhead;
    var nextLine = cm.getLine(nextLineNumber), nextItem = listRE.exec(nextLine);

    if (nextItem) {
      var nextIndent = nextItem[1];
      var newNumber = (parseInt(startItem[3], 10) + lookAhead - skipCount);
      var nextNumber = (parseInt(nextItem[3], 10)), itemNumber = nextNumber;

      if (startIndent === nextIndent && !isNaN(nextNumber)) {
        if (newNumber === nextNumber) itemNumber = nextNumber + 1;
        if (newNumber > nextNumber) itemNumber = newNumber + 1;
        cm.replaceRange(
          nextLine.replace(listRE, nextIndent + itemNumber + nextItem[4] + nextItem[5]),
        {
          line: nextLineNumber, ch: 0
        }, {
          line: nextLineNumber, ch: nextLine.length
        });
      } else {
        if (startIndent.length > nextIndent.length) return;
        // This doesn't run if the next line immediatley indents, as it is
        // not clear of the users intention (new indented item or same level)
        if ((startIndent.length < nextIndent.length) && (lookAhead === 1)) return;
        skipCount += 1;
      }
    }
  } while (nextItem);
}
